From the moment he ascends the throne as emperor, Caligula (Malcolm McDowell) enforces a reign like no other: humiliating and executing anyone who displeases him, sleeping with his sister (Teresa Ann Savoy), organizing elaborate orgies, and embarking on a fruitless invasion of England before meeting an appropriate end. Produced by Penthouse magazine's Bob Guccione, this 1979 production combines lavish spectacle with an A-list cast that also includes Peter O'Toole as Tiberius, Helen Mirren as Caesonia, and John Gielgud as Nerva.